Need More Power!!!

[mtcs]

I have a 2001 jeep cherokee sport. It currently has 190hp...HO motor...I was wondering what can I do to it to increase the horsepower...nothing extreme like changing motors or boreing anything...but simple thing...was thinking of installing a borla exhaust on it...I has 27000 miles on it. Any ideas?
Everything on there is bone stock at the moment.

Thanks
Ben

[dave92cherokee]

Quick easy bolts on's include K&N intake and new exhaust with headers instead of exhaust manifold. Beyond that if you want to put some money into it check into power programmers for your jeep they simply plug into the diagnostic connector and let you reprogram the computer to give you more power.

[neon_rt]

You can get small gains from the 4.0, Hypertech programmer gives around 6-8hp, exhaust system give about 6. Each of these cost about $300, so for $600 you gain 12 hp. Cold air kit will get you about another 6hp, problem I've found with the CA kits is the it is easy to get the filter all wet by splashing in deep puddles and there is an increased possibilty of sucking up water into the engine, hydro-lock is not a happy thing.

[Jeep-King]

The best way too add a significant amount of horse power would be to add some nitrous to it, it does not cost too much and you will fly with that stuff

[neon_rt]

Interesting thing about the 2001 4.0. Because of emisson requirments they had to make the 4.0 way cleaner burning. Those changes reduced the HP by 10HP. To restore the 10HP they redesigned the intake manifold. The manifold for 2000 and up has way better flow than the older ones. If you put a newer manifold on an older engine, you will get a 10-15hp increase (go figure). Now, according to the information I have, the exhaust ports on the newer 4.0 head were redesigned to produce better emissions but flow significantly less. I also noticed that the exhaust manifold on the newer jeeps have dual outlets with minicats attached to each one. If I were looking for HP for my 2001, I would look at finding a 96-99 head and have port (port match to manifolds, polish) and valve (larger back cut valves) work done. Then I would replace the exhaust manifold with a CARB approved header. I would follow that up with a CATCO low restriction Cat with 2.5" in/out (factory one is 2.5 in / 2.25 out) and a 2.5" exhaust. Then the Hypertec programmer to take advantage of the improved flow and increase the rev limiter to 5800 rpm (5300rpm factory).
Next stop, supercharger (or turbo).

[fredjacksonsan]

Wow, cool info.

I was just thinking that changing the axle ratios from stock (3.07 I think) to maybe 3.73 or even 4.10 would give a lot more acceleration and better off roading, without monkeying with the engine one bit.

[neon_rt]

You may have some difficulty with the axle ratio change, check with an expert before you spend any money on that.
It seems to me that some of the axles have different cases that were used for the different ratios. Some of the Dana Models used one size of casing for 3.31 and 3.07 ratio and then used a different casing for the 3:55 - and lower (numerically higher since we are talking ratios) gears.
If that is the case with your axles, you would have to find a Jeep with 3:55s in it and transplant the axles to yours and then either keep the 3:55s or change them to something like 4.10's.